Pilot project: European Web Survey on Drugs: patterns of use

Pilot project: European Web Survey on Drugs: patterns of use

The EMCDDA is currently developing estimates of the size of the drug market in the EU based on data provided routinely to the EMCDDA by National Focal Points. One key component of such market size estimates, for which there is no routine data collection and only limited data available, is the quantities of substances used by different groups of drug users. Read more >>

Live surveys

For this pilot study, the survey was conducted in different countries across Europe. The countries were: Croatia, the Czech Republic, France, the Netherlands, Switzerland and the United Kingdom. The surveys ran at different times.

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Background and context

The EMCDDA is currently developing estimates of the size of the drug market in the EU based on data provided routinely to the EMCDDA by National Focal Points. One key component of such market size estimates, for which there is no routine data collection and only limited data available, is the quantities of substances used by different groups of drug users. The data that is available has tended to come mainly from small scale studies of specific heavy user groups, for example of people entering treatment. On the other hand, General Population Surveys generally do not have sufficiently large samples of drug users to provide robust information on amounts.

For the report Further Insights into the EU drug markets, researchers from Trimbos Institute coordinated an online survey of drug users in seven EU countries, which included the collection of information about amounts used as well as frequency of use and sources of supply. The data collected provided valuable information on the variation in quantities used per occasion by different user groups in different countries. It also demonstrated the potential of this approach for obtaining information from drug users in different countries in a quick and cost-effective manner, while highlighting areas requiring further development to improve the method for the future. 

The EMCDDA is therefore undertaking a pilot project in collaboration with the researchers from the Trimbos Institute to build on the earlier survey experience and develop a system and the capacity within EMCDDA for collecting such data. This would not only be of value to the EMCDDA but would also be a valuable resource for National Focal Points allowing them to obtain valuable information for policy development at the national level quickly and at low cost. If successful, it is anticipated that the range of topics covered would be developed further in the future.

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Aims and objectives

The project aims to develop and test a web survey tool or tools to collect information on the amounts of drugs used by different groups of drug users and to draft guidance for adapting and administering it in different countries. The objective is to assist EMCDDA in the development of a tool that can be offered to National Focal Points with a view to increasing the information available on quantities of drugs used in order to enhance market size estimation at both the national and European level and for use in policy development more widely.

For more information/queries, please contact João Matias.

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Proposed work programme

The aim is to develop a web survey module and accompanying guidance that can be used by National Focal Points to collect information on topics, such as amounts of drugs used by different groups of drug users, that are not feasible to include in General Population Surveys (GPS) because of the small numbers of drug users, particularly frequent drug users, that such surveys cover. While not being representative of the general population, web surveys carefully conducted may nevertheless provide valuable information about variations in use among different groups of drug use that can be a valuable adjunct to GPS. If a common approach is taken to developing the sampling strategies, the same questions are used along with rigorous translation processes then they may also provide useful cross-national comparisons. Thus if this pilot is successful there is the potential to extend the project to include other countries and other topics adding to the European knowledge base In a quick and cost-effective manner.

Building on the questionnaire used for the Further Insights into the EU drug markets report and the lessons learned from that process a web survey tool or tools will be developed to collect information on quantities of drugs used by users of the following drugs: cannabis, amphetamines, cocaine and ecstasy.

The intention is to test this tool and the recommended procedures in 3 countries from the original Further Insights project and 4 new countries covering a range of drug-use characteristics, such as prevalence levels and patterns of use, although the project may be extended to include further countries at a later stage. This survey is being conducted across Europe, currently in Croatia, the Czech Republic, France, Latvia, the Netherlands, Switzerland and the United Kingdom.

Deciding the recruitment strategy to use in each country to ensure coverage of the important user groups for each drug within that country will be important to ensuring the quality of the data obtained. Guidance on doing this will be developed and participant countries will be involved in discussions about the best approaches to share ideas and experience.

The intention is to do the data cleaning and initial analysis at the EMCDDA to ensure compatibility. Countries will be provided with their data for their own use.

Another component of this project is a validation study. The validation study will consist of two parts – reliability study (test/re-test, daily recalls) and validity testing.

Reliability study – test/re-test

The reliability study will have a form of pilot study follow-up and will utilise a subsample of volunteers recruited within the pilot study data collection described above. Contact emails will have to be collected from these volunteers at the end of the pilot study questionnaire. The follow-up questionnaire (administered one week after the first one) will likely be identical to the questionnaire of the pilot survey in order to reduce context bias (with some risk of drop-out).

Reliability study – daily recalls

Similarly to test/re-test, a subsample of volunteers will be recruited through the pilot study questionnaire (possibly within the same question – either follow up or daily check-in, but preselecting frequent users).  

Validity testing

Up to 30 recreational and frequent drug users will be recruited through chain referral techniques based on personal contacts for validity testing that will comprise of cognitive feedback and criterion validity testing. Cognitive testing will be conducted in a form of personal interviews (preferred) or focus groups (in case of time constraints) and will focus on correct understanding of the questionnaire, the techniques of recalling and potential sources of bias (e.g. differences between typical use vs. last use). Criterion validity will be tested using alternative questions measuring amounts of substances consumed.

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Proposed timeframe

A first meeting with the participant countries was held alongside the Head of National Focal Points meeting in November 2015, to discuss the practical details of the study and share ideas.

A web-based forum was created as a tool for the participating countries to share ideas, strategies and documents related to the project.

Data collection will run in different time periods for the different participating countries, starting in March 2016.

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National partners

Croatia: Office for Combating Drug Abuse of the Government of the Republic of Croatia; Faculty of Education and Rehabilitation Sciences, University of Zagreb and Association of Students of Social Pedagogy – Pupovci

Czech Republic: National Monitoring Centre for Drugs and Drug Addiction, Office of the Government of Czech Republic

France: French Monitoring Centre for Drugs and Drug Addiction (Observatoire français des drogues et des toxicomanies, OFDT)

The Netherlands: Trimbos Institute, Netherlands Institute of Mental Health and Addiction

Switzerland: Addiction Suisse in collaboration with the Ecole des Sciences Criminelles of the Lausanne University

United Kingdom: Public Health England

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